Preparation and use of textile threads



Patented Aug. 23, 1938 UNITED STATES PREPARATION AND USE OF TEXTILE THREADS William Whitehead, Cumberland, Md., assignor to Celanese Corporation of Delaware No Drawing.

of America, a corporation Application October 3, 1935,

Serial No. 43,329

4 Claims.

This'invention relates to the manufacture of crepe threads, and fabrics made from the same, which crepe threads contain a mixture of thermoplastic fibres or filaments and non-thermoplastic 5 fibres or filaments. The thermoplastic fibres or filaments may be fibres or filaments containing an organic derivative of cellulose, an outstanding example of which is cellulose acetate.

An object of this invention is the production of crepe threads, and crepe fabrics made from same, which threads contain a mixture of fibres, some of which are thermoplastic. A further object of this invention is the production of crepe fabrics that are resistant to creasing, that have a pleasing crepe texture and that drape well. Other objects of the invention will appear from i the following detailed description.

Crepe fabrics have been formed of yarns consisting of a derivative of cellulose, and of yarns of a derivative of cellulose interwoven with yarns of other materials such as silk, cotton and regenerated cellulose. I have now found that a crepe fabric having highly desirable properties may be formed from yarns containing a mixture of fibres wherein a part of said mixture comprises fibres containing an organic derivative of cellulose and the remaining portion of the mixture comprises natural fibres or non-thermoplastic artificial fibres. The fabrics formed in accordance with the present invention have a pleasing appearance resembling an all silk crepe fabric. The fabric, however, has properties not found in the ordinary crepe fabrics, for instance, it is diflicult to crease, it: has a long life with little or no loss of crepe, e

When the crepe threads of the fabric contain cotton or wool fibres mixed with fibres of an organic derivative of cellulose, the fabric has an exceptional springy hand and is resistant to creas- 40 ing either while dry or damp. This crepe fabric may be held pinched between the fingers for a long period yet upon being released shows no evidence of a permanent crease.

In accordance with my invention, I form crepe threads fromyarns containing a mixture of thermoplastic artificial fibres and natural fibres or non-thermoplastic artificial fibres. The crepe threads may be formed from such yarns by imv parting to the yarns a relatively highdegree of tic fibres of the yarn are at least partially plastic. The thermoplastic fibres of the yarn may be made at least partially plastic bysteaming the thread during the insertion of the twist, particulli larly in the presence of moisture, For the protwist under such conditions that the thermoplas-.

duction of certain types of threads it is also preferable to have present during the insertion of the twist, a compound that will condition the thread such that the steam will affect the thread evenly throughout its length.

The thermoplastic fibres of the yarns to be crepe twisted may be made by extruding a solution containing an organic derivative of cellulose and a volatile solvent through suitable orifices into an evaporative atmosphere as in the dry method of spinning, or into a precipitating medium as in the wet method of spinning. Any suitable organic derivative of cellulose, such as the orgarlic esters of-cellulose and the cellulose ethers, may be used. Examples of organic esters of cellulose are cellulose acetate, cellulose formate, celluose propionate and cellulose butyrate, While examples of cellulose ethers are methyl cellulose, ethyl cellulose and benzyl cellulose. The non-thermoplastic fibres contained in the yarns to be crepe twisted may be natural fibres such as cotton, wool, flax, short lengths of natural silk, etc., or they may be artificial fibres such as' short lengths of filaments of regenerated or reconstituted cellulose. The filaments of reconstituted or regenerated cellulose may be formed by either the viscose or cuprammonium methods of forming such filaments. I

r The yarns to be crepe twisted may contain any suitable proportions of thermoplastic fibres and non-thermoplastic fib'res. When employing cotton, wool, or both cotton and wool as the nonthermoplastic fibres in the yarn, it is preferable to employ from 50 to of thermoplastic fibres. However, any other suitable mixture of thermoplastic fibres and non-thermoplastic fibres may 'be employed.

Yarns may be formed from a mixture of thermoplastic fibres and non-thermoplastic fibres by any method suitable to the mixture of fibres employed, i. e. the yarns may be formed by the woolen, cotton, worsted, etc. method of forming yarns. For instance, a mixture of cotton, wool, cotton and wool and cellulose acetate fibres may be carded to rovings on a woolen card and spun to yarns on a mule spinning machine or on a. ring spinning machine. Furthermore, the yarns to be crepe twisted may be formed by the cotton meth- 0d of spinning yarn where a cotton card and other cotton-yam forming machinery is employed. I have found that if yarns containing a-mixture of thermoplastic and non-thermoplastic fibres are highly twisted, especially in the presence of steam, the crepe threads produced may be woven into a riabric which produces a substantial amount of crepe effect upon suitable processing. I have also found that crepe threads containing said mixtures of fibres form a crepe fabric, the type and amount of crepe effect of the fabric formed from said threads depending upon the conditions employed at the time the high degree of twist is placed in the yarns. .For instance, the amount of crepe effect or height of the pebble in the resulting fabric may be regulated by the degree of twist inserted in the yarn, the wetness of the steam employed, or the amount of plasticizing substances present in the yarn, during the insei' tion of the twist.

By employing this invention, it has been found possible to produce crepe threads which yield fabrics exhibiting crepe effects which are not only substantially permanent but the fabrics are also more resistant to creasing than those heretofore made. Moreover, the crepe threads produced in accordance with this invention have an average strength very much greater than that of crepe threads produced by prior methods. Furthermore, by employing this invention the twisting of the yarn is greatly facilitated in that the twistthe desired twist or at least lead to a very weak and useless thread.

In crepe twisting of yarns it is often difflcult by mechanical means to obtain an even application of steamto the yarn or, as sometimes happens, the yarn is not uniform throughout its length in its adaptability to be plasticized by steam.. Therefore, for the purpose of obtaining an even effect of steam on the yarn, it is preferable to treat the yarn at any time prior to inserting therein the high degree of twist with a lubricating material containing a plasticizer for the thermoplastic fibres of the yarn. The lubricating material may be made by mixing a plasticizer for the thermoplastic fibres with an oil and applying the same to the yarn by means of rollers or wicks prior to twisting to a crepe thread. The plasticizers and oils may be incorporated in the thermoplastic fibres during their formation or at any time prior to being mixed with the non-thermoplastic fibres.

The plasticizers may also be incorporated in the thermoplastic fibres by adding same to the spinning solution from which they are formed. Any suitable plasticizer for the thermoplastic material may be employed. For instance, tri-aryl phosphates, tri-butyl phosphate, di-methyl phthalate, di-butyl phthalate, di-ethyl tartrate and like plasticizers have been found to be suitable plasticizing agents. Other agents having a swelling or softening action on the thermoplastic fibres may be employed, for instance, acetic acid, acetaldel yde, etc. If desired the plasticizer may beemployed without the addition of an oil. Any suitable animal, vegetable or mineral oil that has a lubricating property on the particular yarn being crepe twisted may be conveniently used. Examples of suitable oils for lubricating the yarn are olive oil, teaseed oil, light mineral oil, sulphonated olive oil, castor oil, sulphonated naphthenes, etc.

weighting metal compounds, for example, tin compounds.

In carrying out the process of the present invention twisting may be effected on a device of the kind in which the yarn is drawn off over the end of a rotating package through a guide fixed preferably substantially in line with the axis of rotation of the package and is thereafter wound on a bobbin or the like, the yarn being passed, on

its way from the guide to the bobbin, through' steam. In this way, the yarn is subjected to the action of steam during the actual application of a substantial amount of the twist, or to the action of both steam and moisture if it is passed through steam under such conditionsthat moisture is present.

On the other hand, any other suitable crepe twisting device may be employed in conjunction with steaming. For example, a ring twister or down stroke ring twister may be used for the crepe twisting of the thread. As examples of such devices may be mentioned fiyers and the floating ring device described in British Patent No. 304,806 to British Celanese Limited and others.

Steaming may conveniently be effected by allowing the thread to pass through a suitable chamber supplied with steam preferably under such conditions that moisture is present.

chamber is provided with small holes, top and The bottom, to permit passage of the thread, and also with a steam inlet. If desired, a single steam chamber may be arranged to serve a number of twisting devices, the chamber being provided with inlet and outlet holes for the passage of each yarn. Such an apparatus may conveniently consist of a horizontally positive chamber of suitable shape mounted over a row of twisting devices and provided with eyes of porcelain, stainless steel, or other suitable material at appropriate points on top and bottom for the entrance and exit of the yarns. The cross-section of the chamber should be of sufllcient size to afford the yarn the requisite length of .travel in the steam. Alternatively, a chamber having a smaller cross-sectional area may be used, in which case the chamber may be provided with hollow nipples communicating therewith and through which the yarn passes, the nipples being of sufficient length to provide, together with the size of the chamber, the requisite length of travel in the steam.

The presence of the desired moisture may be assured by supplying wet steam to the steaming device and/or by arranging for the condensation of steam. Wet steam may be conveniently produced by passing steam through water at suitable velocity. For instance, small traps for condensed water may be provided at suitable intervals in the steaming chamber and steam injected therethrough by means of small pipes or orifices. Another method of ensuring the presence of moisture is to wet the thread with water. For example, the bobbins of yarn may be wetted before the twisting operation or, which is preferable, water may be applied to the yarn by means of a wick or other device after the thread leaves the spindle and prior to its entering the steaming device. In place of or in connection with the wetting of the yarn with water there may be applied thereto a solution of a plasticizer. For instance, there may be applied to the yarn an aqueous solution of a mono or polyhydric alcohol. Ex-

amples of suitable alcohols are methyl alcohol, ethyl alcohol, glycerine, glycol, etc. The aqueous solutions may contain from 20 to more than 7.5.

of alcohol. Non-aqueous solutions of plasticizers may be employed.

Steam at slightly above atmospheric pressure, say 1 to 2 centimeters of water, is most conveniently employed. If desired, however, the steaming may be effected with steam at any desired super-atmospheric pressures, e. g. steam at 10-25 lbs. per square inch. When employing a downstroke twisting device the steam may be employed at reduced pressures, say a pressure of a fraction of a centimeter of water.

A steaming treatment of relatively short duration, such as may be secured by passing the yarn at a speed of from 2 to 10 meters per minute through say from 1 inch to 6 inches of steam, has been found to give satisfactory results. Lengthier treatments may, however, be employed. For example, the yarn may be passed at the said speeds through 6 to 12 inches of steam.

The thermoplastic fibres of the yarns, when subjected to the twisting operation in the presence of wet steam, very readily undergo stretching particularly if theyarns have incorporated therein a plasticizer. This stretching of the thermoplasticfibres effects a compacting of the threads during the twisting operation which results in a crepe thread having substantially no greater denierthan that of the yarn prior to twisting. It has been found. that when a yarn containing thermoplastic fibres is crepe-twisted by my process, 1. e in the, presence of steam, the denier of the resultant thread is, in general, owing to the stretch imparted to the thermoplastic fibres and the slipping of said fibres coniained therein, less and sometimes substantially less than if the thread were simply crepe-twisted without steam. In the case of heavy threads, 1. e. those having a denier above 200, while there may be a denier increase between the yarn prior to twisting and subsequent to twisting, a good crepe effect is nevertheless attained. The combined action of drafting and stretching of the thermoplastic fibres results in a compacting of the thread.

The degree of twist applied in accordance with my process may vary within wide limits. A feature of my process is'that it enables a very high degree of twist to be applied to the yarn wi hout producing a weak crepe thread such as are obtained when similar threads are prepared without steaming. My process also enables the use of a crepe thread having a reduced number of turns per inch to produce the same type of crepe effect as are yielded'by former processes wherein threads having a greater number of turns are necessarily employed. My process, moreover, permits of the insertion of a twist of a quality which is impossible of attainment without the presence of the steam during the twisting operation. This is important since it enables to be produced crepe fabrics having very. pronounced crepe eflects. The crepe figure can be regulated according to requirements. The degree of twist desirable in any particular case depends upon a number of factors such as the precise efiects required, and the denier and number of fibres in the thread or the type orposition of the thermoplastic fibres in the thread. For example, threads of a denier, equivalent to a number 12 yarn numbered according to the Cut System may be twisted to about to 70 or more turns per inch.

By my process highly twisted crepe threads may be produced in which the' fibres are extremely closely packed. As appears from amicroscoplc examination of the cross-section of threads twistedin accordance with this invention, the fibres are squeezed together into substantially as close contact as possibler Under certain conditions the fibres of the thread are squeezed together in such a degree as to cause some distoriton of the cross-section of at least some of the fibres.

The highly-twisted crepe threads may be incorporated in the fabrics in various ways, for example, the weft alone may be wholly or partially composed of such threads or the warp may also contain them. Valuable fabrics may be produced by employing in the warp threads of relatively low twist, and in the weft both crepe threads having a left-hand twist and crepe threads having a right-hand twist or pairs of threads of left-hand twist alternating with pairs of threads of right-hand twist.

If desired, crepe threads containing mixtures of thermoplastic fibres and non-thermoplastic fibres may be associated in the fabrics with highlytwisted crepe'threads of other materials, e. g.

crepe threads of natural silk, regenerated cellulose, organic derivatives of cellulose or those produced by other processes. Where the fabrics contain threads of low twist, all of the threads may be of cellulose acetate or partly of cellulose acetate and partly of other material such as natural silk or regenerated cellulose.

Fabrics containing highly-twisted crepe threads prepared in accordance with this invention may be scoured in a cold bath to remove a part or all the plasticizer present in the threads and subsequently scoured, for example, in the manner adopted in connection with fabrics containing highly-twisted threads of natural silk. Enhanced crepe effects may be obtained by employing scouring or other aqueous creping baths at or near the boiling point of the creping medium employed. The fabric may be, in accordance with this invention, caused to crepe by immersing the same in a bath containing up to 10 grams or more per litre of soap, the bath being maintained at about 96 to 105 C. Temperatures above 100 C. are not necessary. However, such temperatures may be employed where the scouring is performed under pressure and/or heavily salted baths are employed. The period of treatment in the heated bath may vary about 1 to 30 minutes or more. The delustering effect of all high temperature scouring baths upon fabrics containing threads of lustrous cellulose acetate may be minimized by incorporating therein protective salts or sugars.

As illustrations in describing this invention and not as limitations, the following examples are given: Example I A mixture consisting of 70 parts by weight of fibres containing cellulose acetate and 30 parts by weight of wool fibres are run through a woolen card machine to form rovings. The rovings are twisted on a mule spinning device to form yarns containing a twist of from 4 to 10 turns per inch.

subjected to a wet steam treatment. The twisted threads are woven into a fabric and the fabric is treated for ten minutes in an aqueous bath mainheavy and uniform crepe effect produced therein, which crepe effect has an exceptionally long life. The fabric soproduced also has a springy hand. and is diflicult to crease.

Example II 'A mixture consisting of 70 parts by weight of fibres containing cellulose acetate and 30 parts by weight of cotton fibres are run through a cotton card machine to form slivers. The slivers are condensed and run through draw-frames to form rovings. The rovings are twisted on a downtwisterrusing the fiyer principle to form rovings containing about 1 turn per' inch twist. The rovof twist thereto, say from 30 to 50 turns per inch of twist. The insertion of this high degree of twist is effected while passing said yarns through a steam chamber where they are subjected to wet steam treatment. The twisted threads are woven into a fabric and the fabric is treated for ten minutes in an aqueous bath maintained at 99 C. The fabric thus treated has a heavy and uniform crepe effect produced therein, which crepe effect has an exceptionaly long life. The fabric so produced also has a springy hand and is difficult to crease.

There may also be formed and processed in accordance with this invention double threads, e. g. threads containing a yarn consisting of fibres of an organic derivative of cellulose twisted together with a yarn formed of suitable fibres of non-thermoplastic materials. This invention is also applicable to yarns formed by doubling a yarn consisting of fibres of an organic derivative of cellulose with a yarn consisting of continuous filaments or regenerated cellulose, reconstituted cellulose, silk or other continuous filament nonthermoplastic material.

In the appended claims, the term plasticizer" include plasticizers,

- tained at 99 C. The fabric thus treated has a upon the filaments containing organic derivatives of cellulose at the temperature of the steam treatment, several representative examples of which are given above. This term is intended to softeners and swelling agents.

It is to be understood that the foregoing detailed description is given merely by way of illustration. and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent isz' 1. Process for the production of highly twisted crepe threads of improved characteristics, which comprises steaming a thread comprising a mixture of non-thermoplastic fibres and fibres containing an organic derivative of cellulose, and

cre'pe twisting the thread while the thread is subjected to the action of the steam at the point where the twist is inserted.

2. Process for the production of highly twisted,

comprises steaming a thread comprising a mixture of non-thermoplastic fibres and fibres containingcellulose acetate, and crepe twisting the thread while the thread is subjected to the action of the steam at the point where the twist is inserted and under such conditions that moisture is present.

4. Process for the production of highly twisted crepe threads of improved characteristics, which comprises incorporating a plasticizer in a thread comprising a mixture of non-thermoplastic fibres and fibres containing cellulose acetate, steaming said thread and crepe-twisting the same while it is subjected to the action of the steam at the point where the. twist is inserted and under such conditions that moisture is present.

WILLIAM wrn'rarman. 

